An album page in the Benjamin K. Miller collection, owned by the New York Public Library and currently on loan to the National Postal Museum in Washington, displays a block of four orange 30¢ Benjamin Franklin stamps with gauge 10 perforations on unwatermarked paper.

The block of four 30¢ Franklin stamps had no Scott catalog number when Miller owned it. Today, those stamps are listed as Scott 476A.

Miller’s note, adjacent to the block of four stamps, reads, “This is the stamp of controversy. I believe in it.” Images from the Miller collection courtesy of the New York Public Library.

Miller’s note called attention to Percy McGraw Mann’s advertisement in the June 21, 1918, issue of Mekeel’s Weekly Stamp News, which promoted the 30¢ Franklin perf 10 unwatermarked stamp as “one of the rarities of the 20th Century.”

By reproducing earlier postmarks of three towns — Percy, Miss.; McGraw, N.Y; and Mann, Pa. — Percy McGraw Mann created a clever corner card that advertised his stamp business on this Nov. 27, 1917, registered special delivery cover. He was the first writer to report the discovery of 30¢ Franklin stamps, gauge 10, unwatermarked.

Mann’s antagonist Joseph B. Leavy, who denied that the 30¢ Franklin with gauge 10 perforations had been issued on unwatermarked paper, was curator of philately for the Smithsonian Institution at the time of his dispute with Mann, and became editor of the American Philatelist in the fall of 1918. Leavy used his business corner card envelope to mail this Dec. 17, 1918, first-flight cover from New York City to Bellefonte, Pa.

In 2011 the American Philatelic Expertizing Service issued APEX certificate No. 197576, which recognized this November 2, 1916, registered cover as the earliest documented use of the imperforate green 1¢ George Washington stamp on unwatermarked paper (Scott 481), as of the certificate date. When author Ken Lawrence lifted the stamps to verify in fluid that they were unwatermarked, he observed one faint S-shaped “ghost” image on the otherwise plain paper. Reports of such irregularities had caused confusion among collectors when unwatermarked paper was first introduced, and continue to sow mischief almost a century later. Photo courtesy of APEX.

Two unused marginal blocks of four stamps with original gum viewed in Clarity watermark fluid illustrate features pertinent to the Scott 476A controversy. The 30¢ Franklin (Scott 420) block on the left shows that watermarks are often difficult to see on stamps printed in orange ink, but they emerge clearly in the unprinted top selvage. The carmine 2¢ Washington (Scott 482) block on the right shows that early prints on unwatermarked paper often show faint irregular ghost patterns that simulate watermarks, subtle but evident here by comparison with the less patterned background of the watermarked block. If amplified by a digital imaging device, some of these impressions might more strongly resemble parts of single-line watermark monograms. Photo courtesy of Ellen Peachey.

Although watermarks can be difficult to detect on stamps printed in orange ink, many examples of Scott 476A — the unwatermarked 30¢ Franklin with gauge 10 perforations — have attached marginal selvage that shows no trace of a watermark when examined in fluid. The Philatelic Foundation declared this stamp to be genuine on certificate No. 129672. Photo courtesy of Robert A. Siegel Auction Galleries.

This stamp — position 44 from the plate 6917 pane first reported by Mann in September 1917 — exemplifies the controversy. In 2005 the Philatelic Foundation certified it as Scott 476A, the unwatermarked rarity. In 2006 Professional Stamp Experts certified it as Scott 439, the common variety with single-line watermark. The Foundation again certified it as the scarce unwatermarked variety, Scott 476A, in 2014. Photo courtesy of the Philatelic Foundation.

“This is the stamp of controversy. I believe in it. BKM,” wrote Benjamin K. Miller, who donated his magnificent collection of United States postage stamps to the New York Public Library in 1925 — the most complete U.S. stamp collection that anyone had assembled up to that time. At present the Miller collection is on long-term loan to the National Postal Museum in Washington, D.C., where visitors can inspect at close hand the rarities he collected.

In the note attached to his album leaf, Miller was referring to a block of four 30¢ orange Benjamin Franklin stamps with gauge 10 perforations on unwatermarked paper mounted on that page. He included details of how and when he had acquired it: “Purchased from Percy McG Mann Dec 21 1918. Only 143 copies known. Ad in Mekeel’s June 21 1918 p 214.”

(Disclosure: In 2006 I wrote, “Long after Miller died, his faith was vindicated,” in the book Rarity Revealed: The Benjamin K. Miller Collection by Scott R. Trepel with Ken Lawrence, published by the Smithsonian NPM and the NYPL as a companion to the exhibit. About a year after I wrote that sentence, the controversy erupted anew, but I have not changed my opinion. I have never had a financial interest in the outcome.)

Today the stamp is listed as Scott 476A, but in Miller’s day only the Stanley Gibbons catalog listed it, and only briefly. In his note, Miller sided with the believers, led by Percy McGraw Mann, the Philadelphia dealer who first reported a discovery of this stamp issue. By omitting it from their listings until 1973, for 55 years the Scott catalog editors tacitly sided with the deniers, led by Joseph B. Leavy, curator of the national stamp collection at the Smithsonian Institution and editor of the American Philatelist, who insisted that no such stamp had been issued.

Before exploring Mann’s evidence and arguments as a believer, and Leavy’s as a denier, I shall review the evolution of perforation and paper standards for Washington-Franklin sheet stamps that gave birth to this controversy.

Perforation Changes in the Washington-Franklin Era

From 1861 until 1910, United States postage stamps were issued either with gauge 12 perforations or imperforate. In 1910 the perforation standard for coil stamps changed to the coarser gauge 8½, because gauge 12 perforations had proved to be too fragile for processing on mechanized coiling equipment. But gauge 12 remained the standard for perforated sheet and booklet stamps until 1914.

All three formats — sheet, booklet and coil stamps — changed to a gauge 10 standard in 1914, but not as smoothly as planned. Beverly S. King and Max G. Johl explained in their book The United States Postage Stamps of the Twentieth Century, Volume 1 1901-1922, “The 10 gauge perforation had been satisfactory for coil stamps but the sheet stamps with this perforation proved difficult to tear apart. The public, used to the brittle 12 perf, found the 10 perf very often resulted in tearing the stamps and a wave of criticism swept the country against this latter variety.”

I have not seen evidence of a widespread groundswell of protest, but evidently the Post Office Department received enough complaints that the Bureau of Engraving and Printing experimented with gauge 11 perforations on the carmine 2¢ George Washington stamp of 1915, during the period when stamp paper included single-line USPS watermark monograms. Those experimental stamps, listed as Scott 461, are scarce today.

The gauge 11 test was eventually deemed a success, but parsimonious Post Office Department and BEP officials postponed the changeover to that standard until existing gauge 10 perforating wheels wore out, which resulted in a delay until March 1917. Meanwhile, except for experimental 2¢ Washington stamps (Scott 461), gauge 10 perforations remained the standard for sheet and booklet stamps issued from 1914 to 1917, including the 30¢ Franklin.

Paper Changes in the Washington-Franklin Era

In 1895 the BEP began printing postage stamps on paper manufactured with USPS watermark monograms called double-line, which meant capital letters drawn so that a stroke on each side outlined a hollow enclosed section. Before 1895 only stamped envelopes had been watermarked. In 1910 the USPS monogram changed to capital letters called single-line because they consist of single solid strokes with no empty enclosed parts. The annual report of the Third Assistant Postmaster General explained:

In April the Director of the Bureau of Engraving and Printing stated that a reduction of the size of letters composing the watermark on our new stamp U S P S (representing United States Postage Stamps,) would increase the strength of the paper and give it a more uniform thickness. He submitted a new design in which the letters, though reduced in size, were so placed that a portion of the watermark would appear on each stamp. The change was duly authorized and postage stamp paper now being manufactured bears the new watermark.

Use of watermarked paper continued until 1916, but came to an end that summer. King and Johl wrote:

The paper contract between the Bureau of Engraving and Printing and the paper mills expired June 30, 1916, and on the following day a new contract went into effect under the terms of which the paper to be furnished for printing postage stamps was to be unwatermarked, and all stamps printed after August 17 were issued on this unwatermarked paper and were perforated ten.

Collectors did not become aware of the paper change immediately, but in the October 1916 Philatelic Gazette, Philip H. Ward Jr. reported:

Since August 17th the postage stamps engraved by the Bureau of Engraving and Printing have all been on unwatermarked paper Perf. 10. The paper is similar in every way to the old article with the watermark omitted and is manufactured by the same firm. …

The new Perf. 11 wheels will not be put into operation until the old Perf. 10 wheels have worn out and then the change will be gradual, each wheel being changed as it wears. … From the looks of the old wheels the new Perf. 11 will not appear for several months.

In the meantime we will probably have all except the higher denominations, Perf. 10 unwatermarked.

Even after learning of the change, collectors experienced difficulty identifying unwatermarked stamps, because many of them exhibited “irregular thin spots in the form of thin lines, curled and twisted” when examined in fluid, as Mann reported in the Sept. 8, 1917, Mekeel’s. He had submitted a sample block to BEP director Joseph E. Ralph, and he published Ralph’s explanation:

Your letter of the 20th instant was duly received, enclosing a block of twenty-five 2-cent stamps, which seem to have a watermark in the paper on which they are printed, but which you cannot decipher, and request me to advise you if this Bureau is again using watermarked paper for the stamps. In reply, I return the block of twenty-five 2-cent stamps and beg to state that there is some slight irregularity in the paper due to ‘pick-up’ of the dandy or wires of the paper machine that might be mistaken for watermarking, but it is entirely accidental. Postage stamp paper now used is not watermarked, and we will probably never again use watermarked paper for such stamps.

Other experts had alternative explanations for these random unintended images that had no purpose. I doubt anyone today can be certain of what caused them, but these irregularities that Mann and Ralph described on early batches of Washington-Franklin unwatermarked paper are analogous to so-called “stitch watermarks” on 19th-century stamps, which the Scott catalog describes as “a type of watermark consisting of a row of short parallel lines. This is caused by the stitches which join the ends of the band on which the paper pulp is first formed.”

To give a descriptive name to these eccentric 20th-century patterns, which were reported and analyzed before any unwatermarked 30¢ Franklin stamps had been discovered, I dubbed them “ghost watermarks” several years ago, a term that has gained some acceptance among specialists. A notable example appeared when a cover was submitted to the American Philatelic Expertizing Service in 2011 as the earliest documented use of the imperforate green 1¢ Washington stamp on unwatermarked paper (Scott 481).

The stamps consisted of a block of eight and a strip of four, with the strip showing part of plate No. 7535 from the first set of 1¢ plates printed on unwatermarked paper. However, that plate had been sent to press before the paper change, so the stamps might have been Scott 408 with single-line watermarks.

To check the owner’s identification, I had to lift the stamps. When I dipped the block in fluid, it showed no trace of a true watermark, but the strip showed a faint image that resembled an S or a wave, which I recognized as a ghost watermark, not part of a USPS monogram.

My watermark detection system employs a black tray large enough to accommodate not only the subject stamp, strip or block in watermark fluid, but also a reference block that shows a complete watermark monogram for comparison (in this case, a block of Scott 408) and another with no watermark (481).

If I had viewed just a single stamp showing this feature I might have considered it to be watermarked. Studied carefully by this comparative method, the stamps on this cover were clearly multiples cut from an unwatermarked sheet with a barely visible anomaly in one small area that resembled part of a watermark. That faint image did not match or approximate the watermarked reference. In every respect but the ghost on the smaller strip, the stamps did match my unwatermarked reference. The cover was properly identified and received APEX certificate No. 197576 as Scott 481.

Printing History of the 30¢ Franklin Stamp

Stamps of the 30¢ Franklin design were first issued in April 1914, primarily to use on parcels after dedicated parcel post stamps had been phased out. Four 400-subject plates were prepared and sent to press — Nos. 6899, 6911, 6914 and 6917. At that time, gauge 12 was the perforation standard, and stamp paper included single-line watermarks. Those stamps are listed as Scott 420.

A few months later, the same plates went back to press. By the time those prints were finished and issued in September 1914, gauge 10 had become the perforation standard, listed as Scott 439. A third printing in June 1916, about two months before the change to unwatermarked paper, replenished the depleted inventory with another Scott 439 batch.

The fourth printing of the same four plates occurred from March 13 to 17, 1917, after the switch to unwatermarked paper. The BEP had begun to replace worn-out gauge 10 perforating wheels with new gauge 11 wheels at that time, but did not complete the changeover until May 10. It’s likely that some of the printed sheets were finished on one or more old perforators, yielding stamps now listed as Scott 476A, and that others were finished with gauge 11 perforations, Scott 516.

The fifth printing of the 30¢ Franklin in November 1917 and the sixth in February 1918 continued to employ the same printing plates, but they were replaced by a new set in April 1918 and for the rest of that year. Production of Scott 516 continued through September of 1923.

The complete plate activity list can be found in Bureau Issues Association (since renamed United States Stamp Society) Research Paper No. 5, Printing History of Washington-Franklin 3¢-$5 Denominations by Wallace Cleland, published in 1994. Until Cleland examined and published BEP press room records, false reports had hampered proper understanding of Scott 476A. For example, King and Johl wrote:

The Bureau’s aid was asked and a checkup by them proved that this denomination perforated 10 on unwatermarked paper COULD NOT EXIST as the thirty cent plates did not go to press between the time the Bureau started using unwatermarked paper and the last flat plate perforating machine had been changed to 11 gauge.

In a September 1990 United States Specialist article titled “Printing History of the 15¢ and 30¢ Denominations of Franklin Head Stamps, Series of 1911,” Cleland commented:

The Bureau obviously did not consult its own records very accurately. The March printing clearly fell between the time the last delivery of watermarked 30¢ stamps was made on December 11, 1916, and the time the last perforation wheels were changed on May 10, 1917. It is true that the first delivery of unwatermarked stamps was on April 12, 1917, and the stamps were not issued until May 1917, but there is no reason why some of this March printing could not have been perforated 10.

Believers vs. Deniers in 1917

By the end of 1916, all current Washington-Franklin denominations except for 30¢ and 50¢ had been reported with gauge 10 perforations on unwatermarked paper. The 50¢ Franklin appeared in March 1917. The April 7, 1917, Mekeel’s “Chronicle of New Issues and Varieties” column reported:

Through the courtesy of C. Edward Wright we are able to present some interesting information for U.S. collectors. He advises us that the 30c value will not appear on unwatermarked paper with 10 perforation.

Wright had previously chronicled the issue dates of every 20th-century stamp based on information supplied by BEP officials, so this was taken as an authoritative report. But his timing was odd, considering that gauge 10 perforators were still in use on that date and for a month more. Even if there had been no intention to finish additional 30¢ sheets on that equipment, contingencies in the finishing room might have changed the plan.

With hindsight it’s easy to see how Wright’s report probably forestalled a thorough search for the variety when it might first have been distributed, but not everyone had been deterred. In the September 15 Mekeel’s, Mann wrote:

The 30c, perf. 10, on unwatermarked paper, has appeared, and unused blocks have been shown to us by Mr. Wm. S. F. Pierce. Without question, this will be one of the scarcest recent U.S. stamps, and it is an illustration of the almost worn out saying: “The unexpected always happens.” [Four weeks later, Mann published a correction, writing that “unused blocks” should have been “an entire sheet.”]

Two weeks after Mann’s report, in the Sept. 29 Mekeel’s, Washington stamp dealer H.F. Colman published the first quasi-official denial:

I took this matter up with the Post Office Department and they informed me that their stock of 30c stamps printed on watermarked paper perf. 10 was so large that it lasted over the period in which stamps were printed perf 10 on unwatermarked paper, so that the records show that none of these stamps have been issued thus.

Mann replied in the Oct. 13 issue:

Mr. J.E. Ralph informs one or our correspondents, Mr. P.H. Ward, Jr., that the first printings of the 30c on unwatermarked paper took place on March 13, 1917, and that the last machine to be changed over from 10 to 11 perforation was so changed on May 10. 1917. So it was during this period of almost two months, that some of the 30c on unwatermarked paper were perforated 10.

In the Oct. 27 issue, Mekeel’s editors sided with Mann: “We can assert unqualifiedly that the thirty-cent exists perforated 10 in unwatermarked condition.”

Joseph B. Leavy in Denial

Attempting to disprove the existence of stamps that another person owns might seem like a daunting challenge, but Leavy made a valiant attempt in the November 1917 Philatelic Gazette. Leavy’s style of debate cast aspersions on Mann without actually naming him, sought to discredit Mann’s sources while promoting the authority of his witnesses, and cited circumstantial evidence that the stamps could not have been made:

A short time ago an advertisement appeared offering for sale, at high prices, blocks of 30c no watermark perforated 10. As I have been positively assured that this denomination has never been perforated 10, except on watermarked paper, I immediately proceeded to investigate the matter. I found that one lot of 4000 sheets of 400 of the 30c on no watermark paper was perforated during the period in which the wheels were being changed on the perforating machines. I was positively assured by the superintendent of the perforating division of the Bureau of Engraving and Printing that this lot had been carefully watched and that all the sheets had been perforated on the changed machines and were in consequence all perforated 11.

An inquiry disclosed the fact that exactly one half of the lot of 4000 sheets of 400 of the 30c no watermark that had been perforated during the period in which the wheels were being changed was still in the vaults of the Bureau of Engraving and Printing. …

The Bureau of Engraving and Printing was ordered to open the packages containing these sheets and examine each and every sheet as to perforation; this was done and all the sheets proved to be perforated 11. So it is not possible for the 30c denomination to exist perforated 10 on the regular no watermark paper. [Leavy’s boldface emphasis.]

I am skeptical about this report, partly because neither the Post Office Department nor the BEP used the philatelic method and scale of gauge measurement to describe perforation spacing, and partly because this suggests an intentional omission that had not applied to any other stamp denomination. At the very least, Leavy translated shop floor terms into hobby language, but he also might have distorted facts in the process.

Later in the article, Leavy suggested that some sheets of the paper might have been manufactured in error with weak or omitted watermarks, a theory also presented in an article by Ward in the same issue. In the Dec. 1 Mekeel’s Mann acknowledged the Philatelic Gazette opinions, but stood his ground. In the June 1918 issue of his house journal Mann’s Stamp Magazine, he published a 36-page treatise on the subject.

Mann sold the complete unbroken plate 6917 discovery pane of 100 stamps to a collector whose identity has not been reported. He dispersed the balance — 43 stamps from a plate 6914 partial pane — to Miller and others. Those sales comprised the entire known quantity from Pierce’s discovery, which Pierce had purchased at a New Jersey post office.

Lacking catalog recognition, the variety appealed only to dedicated specialists such as Miller. After Mann’s inventory had been depleted, the subject disappeared from advertisements and was seldom a topic of articles until after King and Johl wrote their book.

Expert Recognition of the 30¢ Franklin perf 10 unwatermarked

In 1947 Robson Lowe Inc. submitted the plate 6917 pane to the Philatelic Foundation for certification. PF certificate No. 547, signed by the renowned philatelist Theodore Steinway and U.S. specialists Norbert J. Eich and George R.M. Ewing, declared, “we can find no trace of a watermark.” Despite that stellar affirmation, the pane vanished from public view until Boston dealer Jack Molesworth resubmitted it to the Philatelic Foundation in 1960.

Herman Herst Jr. reported that Molesworth had acquired it from the estate of a New Jersey collector named Jim Hughes. It’s possible that Hughes had been Mann’s anonymous buyer, but it’s also possible that Hughes was the collector who had dis­covered a second pane that Molesworth also acquired at about the same time.

This time PF certificate No. 11704, signed by Louise Boyd Dale, read, “it is unwatermarked and should be Scott #476A” — the first time that catalog number was proposed. The Scott editors still were not persuaded, but the stamp did get listed in the 1961 Minkus New American Stamp Catalog as No. 362A, followed by this explanation:

A full sheet of 100 stamps of the 30¢ denomination has been discovered without any trace of watermark. This fact has been authenticated by The Philatelic Foundation whose expert committee issued a certificate on February 1st, 1960 to the effect that “U.S.A. 1916 30¢ orange red, complete mint sheet … is unwatermarked. …”

Actually the Philatelic Foundation had examined and certified two complete panes of the stamp, the second one printed from plate 6911 (also owned by Molesworth), and later a plate 6914 marginal single. The examining experts were Herbert J. Bloch and John R. Boker Jr. Both panes had passed two tests. First and most obvious, no watermark could be detected in the clear marginal selvage of either pane. Second, because watermarks can be difficult to view on stamps printed in orange ink, the experts made negative photographic contact prints of both panes.

The prints revealed no watermarks on the submitted panes, confirming the experts’ direct visual examination, but watermarks did clearly appear on adjacent orange reference stamps included in the prints. Many years later Molesworth loaned me the negative print made of one of his panes to see the result for myself.

After Molesworth sold the first pane to Arizona collector R.D. Brown, it was pictured on the front of the March 1961 American Philatelist.

In the cover story, editor James Chemi wrote, “Minkus has apparently brought this controversy to a conclusion by giving the 30-cent stamp the apparently long overdue recognition.” Brown exhibited the pane at the 1961 Aripex stamp show, which hosted the annual spring meeting of the American Philatelic Society.

A decade later Arizona dealer Lawson Nagel submitted single stamps and blocks to the Philatelic Foundation for certification, numbered as to their original position on the plate 6917 pane. Those were certified as genuine Minkus 362A stamps. By this time at least 243 examples of perf 10 unwatermarked 30¢ Franklin stamps had been bought and sold. Finally, 1973 editions of the Scott Standard Postage Stamp Catalogue and the Scott SpecializedCatalogue of United States Stamps and Covers listed them as Scott 476A. That listing has continued ever since.

Meanwhile, though, expertizing previously certified single stamps had become more difficult after the original panes and large multiples were broken up and dispersed. In the Philatelic Foundation’s 1988 Opinions V book, William T. Crowe explained:

An expertizer has his hands full when he tries to determine whether an individual example really is unwatermarked. If presented with a single, the slightest trace of what might be a watermark will lead to its being identified as #439. A block presents some possibilities that a single does not. A very slight trace of what might be a watermark can be followed to adjacent stamps, since the spacing between watermark letters is consistent. Thus, if what appears to be a touch of a watermark on one stamp does not follow through to the others, it can safely be dismissed. On the other hand, additional traces on any other stamps in the multiple will lead to an opinion that the stamps are #439.

Crowe’s title, “The Stamp That Should Not Exist,” hinted at his suspicion that Scott 476A is an error, not an intentionally issued stamp, “The author feels that this stamp does exist, but it will probably never be known why it exists.”

2007: A New Generation of Deniers

In October 2006, Professional Stamp Experts issued certificate No. 01074001, which declared one stamp from the Molesworth-Brown-Nagel pane to be “US#439. … It is genuine unused, o.g., never hinged, Pos. 44, Plate No. 6917, with a clear single line watermarked ‘S,’ ” not Scott 476A, the unwatermarked stamp as it had been certified previously by the Philatelic Foundation.

PSE’s claim became the subject of a front-page headline story in the January 15, 2007, issue of Linn’s: “Using the Foster and Freeman Video Spectral Comparator (VSC), the examiners say they detected ‘a very clear “S” watermark on the stamp …” which was accompanied by a picture from the equipment’s imaging recorder. That part of the Linn’s report was accurate, but in explaining how watermarks occur, the story seemed to me to present PSE’s interpretation as a fact:

Because the single stamp examined by PSE is previously certified as coming from one of the two known panes of 100 Scott 476A stamps, the presence of a watermark on one stamp would automatically imply that the other 99 stamps are also watermarked.

As I understood it, that was a deduction, which asserted the issue that should have required proof. The VSC had captured and recorded a digital image of the stamp under light with a wavelength of 715 nanometers — in the infrared part of the spectrum not visible to human eyesight — which strikes me as an odd way to verify a feature whose purpose is to be visually evident.

Unfortunately PSE’s statements were provided by the firm’s president, Michael Sherman, who was not a philatelic expert. Sherman claimed that Crowe, by then PSE’s director of research, “has reviewed all the evidence, and is in agreement with our findings,” but refused to allow me to interview Crowe or any of the examining experts concerning these claims when I raised doubts about PSE’s method in Internet chat board discussions.

Sherman had written in a letter, “These findings support the contention that a number of philatelists have long held — that Scott No. 476A does not really exist, and that purported examples are in reality, Scott No. 439s printed on very lightly watermarked paper.” Viewed in that context, PSE’s result might have been construed as supporting a predetermined conclusion.

2014: Denial Revisited, Not Necessarily Revived

Except for occasional eruptions online, PSE’s announcement fell flat. The 2007 Linn’s report had failed to persuade independent experts, Washington-Franklin specialists,or the Scott catalog editors to reconsider the listing. But last year deniers found another forum and a new advocate to promote their cause.

The renewed attempt to discredit the stamp arrived in an article by Kevin Lowther titled “Scott’s 476A High Watermark, or Believing in Ghosts” in the May 2014 issue of American Stamp Dealer & Collector magazine. Although he had performed original research, festooned his article with 52 superscript numbers and nearly a full page of reference endnotes, and retold a familiar story, Lowther made mistakes and omitted significant details. He claimed that two plate 6917 panes were known, but there was only one, which made a mess of his provenance report.

The PSE story, like the fisherman’s account of the one that got away, seems to have improved with the passage of time. In notifying Linn’s in 2006 that PSE’s experts had found a watermark on one stamp from plate 6917, Sherman had written:“We have examined two stamps from the other sheet (#6911) and believe we see watermarks on those as well. However they are only partial letters, and not yet in the class of the ‘smoking gun’ that we would like to present to the stamp collecting community.” This time around PSE’s former manager J. Randall Shoemaker told Lowther that “The VSC ‘plainly’ revealed watermarks on each of the three examples.”

Although Lowther wrote that PSE had continued to find watermarks on stamps previously certified as Scott 476A, the example he illustrated was the one that PSE had reported in 2006. He did not report that the Philatelic Foundation had certified that same stamp as Scott 476A a second time — in February 2014 — a few months before his article appeared. If PSE has observed and recorded additional examples in the past eight years, especially examples that might have illustrated other parts of a watermark monogram, why did he leave them out?

By that omission Lowther ignored what could have been his most persuasive evidence, if such exists. The original position of each plate 6917 and plate 6911 stamp is known. If a genuine watermark exists on a stamp from either pane, one can predict which monogram letters or parts of letters should exist on other stamps from the pane, and their orientations, in no more than four arrangements. Confirming a second position would have pinned down the possibilities to one layout, which would make it possible for us to map and anticipate all watermark positions on an overlay. Showing evidence that the VSC has confirmed such a prediction would have decidedly strengthened his case. The corollary of this reasoning is that however much a picture of a paper feature on a stamp might resemble part of a watermark, if it does not fit the monogram template for the entire pane, it cannot be a genuine single-line watermark. Ghost watermarks appear to follow no predictable pattern.

On the other hand, Lowther pictured eight Scott 476A lots sold by Robert A. Siegel Auction Galleries between 2000 and 2013, all of which had been certified as genuine by the Philatelic Foundation. He cast doubt on their legitimacy by innuendo. “Auction houses,” he wrote, “have the option of informing potential bidders whether a 476A on offer has been tested by a VSC and whether a watermark — no matter how ghostly — was detected.”

Lowther might not believe in ghosts, but he evidently has faith in magic — tricks that conjure up images of things he can’t see, hear, touch, taste or smell with his own senses — without displaying a twinge of skepticism as to how that might be done or curiosity about why Philatelic Foundation experts and others decline to share his credulity. He wrote as though the VSC is self-evidently superior to a black tray and fluid as a method of watermark detection, but never paused to suggest a reason why watermarks on 30¢ Franklin stamps always hide where no one can see them without the aid of digital technology, or why they never appear in clear marginal selvage.

In a telephone interview PSE representative Caj Brejtfus told me his firm has examined nine stamps previously certified as Scott 476A — stamps from both original panes and the partial pane — and has certified all of them as Scott 439. The most recent two were submitted in 2014. He said the watermarks cannot be seen with the naked eye, but PSE experts believe that gum interferes with the ability to view faint watermarks. When I pointed out that marginal selvage is not gummed, he said that PSE has not had an opportunity to examine one with attached selvage, but he believes the VSC can detect a watermark on any part of a pane.

Brejtfus was unable to tell me the VSC settings that revealed the watermarks because the method PSE applies is to manipulate the wavelength and intensity of illumination until the examiner sees a watermark on the video screen, then to record that image.

Wet Vs. Dry Watermark Detection

Shorn of its majestic aura as an expensive forensic device fitted with a marvelous array of technologically advanced features celebrated on television crime dramas, the Video Spectral Comparator in this philatelic application is the latest entry on the roster of dry watermark detectors.

Every generation of U.S. specialists for the past century has devoutly wished for a better and less messy method than immersion in fluid to detect watermarks, grills, pressed-out creases, chemical stains and other hidden faults, but dry methods have repeatedly disappointed us.

Clever inventors have tried many different methods to achieve a reliable device. The Morley Bright Roll-A-Tector and Insta-Tector use sealed packets of thick dark fluid that is supposed to flow over and enhance a watermark pattern when rolled against the surface of a stamp.

Various models of Safe Signoscopes and Stanley Gibbons’ Detectamark squeeze and illuminate a stamp between thick transparent blocks of polarizing refracting plastic, viewed through a magnifying lens.

Lindner’s Letterscope and Stampscope direct incident light at favorable angles for enhanced contrast of embedded light and dark features of stamps and paper.

Each of these devices is said to work well with some foreign stamps. None work well as detectors of watermarks on U.S. stamps. They fail to reveal some watermarks and mislead with mirages that vaguely resemble watermarks on others. Our experience with these devices has been so uniformly dismal that specialist collectors have always returned to the wet method — viewing stamps in a black tray immersed in fluid, as the reliable test.

In light of this background, one cannot assume that the VSC is a reliable detector of U.S. stamp watermarks. Two aspects need to be demonstrated: first, that a user who applies the same test to every stamp will be rewarded with a correct identification of every double-line watermark, single-line watermark, and error watermark; second, that the device will not appear to report a watermark where none exists. If such proof has been adduced, I haven’t seen it.

For wet watermark detection, many experts prefer to use Ronsonol brand lighter fluid, which is both toxic and flammable. My preference is Clarity, a fluid formulated by Preservation Technologies in the 1990s, at my suggestion, to meet specifications recommended by the American Philatelic Society expert committee, and rigorously tested. It is nontoxic and does not react chemically with stamp constituents, nor does it leave a residue.

Clarity has a higher refractive index than other fluids used for watermark detection, and reveals watermarks, grills, creases and faults at greater contrast. Even so, detecting a watermark on a bright orange stamp is a challenge, which almost always requires viewing a known reference stamp for comparison. Many times I have found that viewing the stamp in fluid through a deep red filter brings a watermark into clear view.

In the case of Scott 476A, at minimum one would have expected to see a side-by-side comparison of a reference watermarked stamp, a reference unwatermarked stamp, and the subject stamp with images shown at identical settings of intensity, contrast, polarity, scanning wavelength(s) and any other adjustable features of the dry device, recorded in a way that they could be independently repeated and verified.

Scientific Experiments Needed

Despite everything I have written here, it’s possible that Mann, Miller, Ralph, Steinway, Eich, Ewing, Molesworth, Bloch, Boker, Dale, Brown, Chemi, Nagel, Herst, Cleland, the Philatelic Foundation, the Scott catalog editors and I are wrong. Even though the preponderance of evidence gathered over almost 100 years supports our collective conviction that our eyes have not deceived us, Wright, Colman, Leavy, King, Johl, Professional Stamp Experts, Lowther and other Scott 476A deniers might be right.

To investigate that possibility scientifically, it’s necessary to devise experiments that can be evaluated without bias, can be independently verified and can be reliably replicated. If the deniers are right, one ought to be able to reveal complete USPS single-line watermark monograms on intact or reconstructed multiples of stamps that believers regard as unwatermarked, not just occasional patterns that resemble parts of letters. If believers are right, one ought to find ghost watermarks on early Scott 516 prints, just as I found one on the unwatermarked imperforate 1¢ Washington strip on the earliest-use cover and on the illustrated block of imperforate 2¢ Washington stamps. If watermark-like images can be found on perf 11 stamps, that would raise considerable doubt about the usefulness of the VSC test.

Let’s gather a large sample of watermarked 30¢ Franklin stamps (Scott 439) and unwatermarked 30¢ Franklin stamps (Scott 516), including large enough blocks of each to reveal complete USPS watermark monograms. Let’s examine every stamp in fluid, and with the VSC at a range of settings, to learn how the two methods of watermark detection compare and to find out whether the VSC results match or differ from the results viewed in fluid. Pay special attention to any watermark-like images that the VSC records on unwatermarked gauge 11 stamps.

Those are my suggestions. No doubt other collectors have more ideas, and among our hobbyists are academic scientists and other professionals who should be enlisted in this project. Perhaps the Institute for Analytical Philately could be recruited to supervise and report the results of such a study.